<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>5标签样式css</title>
    <!-- css 层叠样式表-->
    <style>
      /*
        选择器{
            样式*n;
            ... ...
        }
        */
      #app {
        color: rgb(46, 47, 50);
      }
    </style>
  </head>
  <body>
    <!-- 内联样式 -->
    <!-- px是密度单位 -->
    <p name="app" style="color: blueviolet; font-size: 200px">aaaa</p>
  </body>
</html>
